Mahiru is a young boy with a faintly darker skin tone who typically wears his school uniform, which consists of a gray blazer layered over a red hoodie, gray pants, and white tennis shoes. His hair is dark blonde and tied in a small ponytail, giving him a casual yet neat appearance.

After deciding to become a vampire, Mahiru undergoes a noticeable change in his appearance. He begins letting his hair down and switches to wearing loose, baggy clothing, giving off a disheveled look that Kou describes as “looking tired.” This shift in style reflects his emotional state and the toll his inner struggles have taken on him.

Mahiru is a kind and easygoing person who tries to maintain a relaxed and positive atmosphere with those around him. He is well-liked at school, effortlessly socializing with classmates and teachers, which contributes to his popularity.

However, this cheerful demeanor is merely a facade hiding deep-seated trauma and depression. Beneath his friendly exterior lies resentment toward his family for the emotional neglect he suffered after his older brother’s death. As a child, Mahiru genuinely loved flowers and once dreamed of inheriting his parents’ flower shop, but as he grew older, that affection turned into bitterness—he began wishing the shop and his household would disappear entirely. Like his only real friends, Kou and Akira, Mahiru finds no joy in socializing with his classmates. He feels drained by their constant pressure to hang out and experiences a grim sense of relief after finally revealing his true feelings, even though it results in them attacking him. Originally timid and quiet, Mahiru adopted his late brother’s personality in an attempt to become popular, and though he doesn’t consider his peers true friends, he still feels lonely without them.

After meeting Kiku Hoshimi, Mahiru’s personality takes a drastic turn. He becomes harsh, impulsive, and disturbingly eager to harm humans. However, this behavior stems from his anguish over Kiku’s impending death rather than true malice. Following his confrontation with Kou, Mahiru softens again, his depression becoming more visible in his somber tone and withdrawn behavior. Although he tries to sever ties with his past, Mahiru remains emotionally attached to Kou and Akira, unable to completely let go of the bonds they share.

Kou Yamori

Mahiru and Kou were childhood friends who understood each other deeply. Mahiru admired Kou for his independence but also envied his ability to be content alone. After Kou dropped out, Mahiru often thought about him and later opposed Kou’s desire to become a vampire, though he eventually accepted it and even offered his blood. Their friendship soured when Mahiru became Kiku’s servant and started mocking Kou. Feeling betrayed after learning Kou’s secret, Mahiru ended their friendship. Despite that, he still cared about Kou, keeping a photo of their childhood and regretting how things ended. They later reconciled briefly before Mahiru’s death.

Kiku Hoshimi

Mahiru met Kiku while working at his family’s flower shop and fell in love with her kindness and understanding. Even after discovering she was a vampire, he stayed by her side, entranced by her charm. Though manipulated, Mahiru’s feelings were genuine—he loved Kiku enough to ignore her deceit and remain loyal. When she revealed she would soon die, Mahiru accepted her fate and chose to die with her, preferring that over living without the woman he loved.

Akira Asai

Akira and Mahiru shared a quiet but strong friendship built on mutual understanding. She was one of the few people he could confide in. After Akira was attacked by a vampire, Mahiru grew to despise them but later confided in her again about his wish to become one. Before leaving with Kiku, he bid her a sincere farewell, keeping a photo of the three of them as a reminder of their bond.

Mrs. Seki

After his brother’s death, Mahiru was neglected by his mother, who refused to move on. Though he helped with the flower shop and made excuses for her, resentment grew within him. Later, he confronted her, admitting that he once hated her but now felt nothing. In a final letter, Mahiru revealed that he had planned to kill his parents after becoming a vampire but changed his mind, wishing instead for them to live peacefully after his death.